Book



United States Patent 3,214,193 BOOK Lawrence A. Monroe, Evanston, llL,assignor to R. R. Donnelley & Sons Company, a corporation of Delaware NoDrawing. Filed May 20, 1963, Ser. No. 281,743 4 Claims. (Cl. 28121) Thisinvention relates to a book construction employing in combination withthe usual assembly of paper sheets a combination of adhesives forbinding the paper sheets to the book.

In making certain types of books, particularly those using a patentbinding, it is customary to adhere the back edges of the paper sheetsmaking up the book with an adhesive which may have incorporatedtherewith a loosely woven fabric in order to give strength at the backof the book. Customarily, this adhesive has been an animal protein gluecontaining water. This adhesive has customarily contained glycerinewhich serves primarily as a plasticizer or humectant for keeping theglue flexible.

This type of prior book construction has not been completelysatisfactory, as the adhesive tends to dry out and become brittle sothat the book can be cracked at the back if it is opened up to too greata degree. Furthermore, in order to apply animal protein glue to books,it has been customary to liquefy the glue by adding water and byheating. It has been customary to limit the heating to an uppertemperature limit of 140 F. to avoid the denaturation of the proteinswhich is prone to change their chemical nature when wet above thattemperature, causing loss of their ability to serve as adhesives.Bookbinders customarily apply glue to books wit-h mechanized glue potswhich cannot operate well if the viscosity of the contained glue is muchin excess of 10,000 centipoises. Accordingly, it is usual to add waterin the pots to reduce the Working viscosity to this level, usingmixtures of glue, glycerine, and water whose water content amounts to 30or 40 or more percent of the total mixture.

When paper covers or liners are applied to such wet glues the free waterof the glue tends to diffuse into the paper, softening it, so thatfurther processing and handling of the book, such as conveying, storing,trimming. wrapping, bundling, and shipping may mar or destroy the papercover or liner, if done within eight to sixteen hours after applicationof the glue.

It is known that when water is added to perfectly dry animal proteinglue, the first 20 or 21 percent of water added to the protein becomesbound to the protein, much as Water of crystallization is bound tocertain chemical compounds. It might be thought that a glue of such lowwater content could be used with customary glycerine additions inbookbinding, as the absence of free water from such glues would reduceor eliminate the softening of paper covers and liners previouslymentioned. However, in order to obtain the proper fluidity in the gluepot which is a part of every binding machine for producing books of thistype, it is necessary to heat such an adhesive of low water content toas much as 180 F. or more. At these temperatures the animal glue tendsto deteriorate and lose its adhesive characteristic, so that the gluepot must be frequently emptied and refilled with fresh glue.

One of the features of the present invention is to provide an improvedbook construction that avoids the above difiiculties.

Other features and advantages of the invention will be apparent from thefollowing description of certain embodiments thereof.

In the present invention the book comprises an assemice bly of papersheets having the back edges aligned for binding and with the sheetsbeing bound at the aligned back edges with an adhesive that is in atleast two layers. The first adhesive layer is a conventional bookbinding adhesive including the usual animal gelatin-glycerinewatercombination.

On this first adhesive layer which is applied directly to the back edgesof the aligned paper sheets there is provided a second adhesive layer ofa specific type. This second layer comprises animal gelatin containingapproximately 20% bound moisture, as contrasted to free and separatemoisture; about 50-90% by weight of glycerine based on the total Weightof gelatin plus water. A coumarone-indene resin having a ball and ringsoftening temperature of about 25-55 C. comprises about l020% by weightof the total weight of the gelatin plus Water plus glycerine. Thissecond adhesive is prepared by adding the coumarone-indene resin inmolten form to the other ingredients at a temperature of about F.Adhered to this second adhesive layer is a book cover to complete thebook.

In a book having the characteristics set out in the preceding paragraphthe moisture in the first adhesive layer is retained because the secondadhesive layer prevents passage of the moisture therethrough. This meansthat the adhesive combination at the back of the book retains itsmoisture and remains flexible for an extremely long period of time. Italso means that the cover can be water sensitive and will not be damagedby the water of the first adhesive layer as the second adhesive layerfunctions as a moisture barrier. In addition, the second adhesive layer(which does not readily bond directly to paper) binds the paper sheetsmuch better than when used alone as the first layer diffuses into theadjacent edges of the paper to form a firm bond therewith so that thesecond layer, in turn, is bonded firmly to the first layer.

' A very important advantage of the book of this invention is that thebook can now be trimmed within a few minutes (often within threeminutes) after the second adhesive layer and the cover are installedinstead of the 8 16 hours required with a conventional adhesive binding.Another very important result of this invention is that the glue potcontaining the second adhesive now need only be heated to about 150 F.instead of F, This means that there is less heat degradation of theanimal protein and there is therefore less wasting of adhesive. In theconventional book binding machine the adhesive must be maintained atapproximately 10,000 centipoises viscosity in the glue pot in order tooperate properly.

Example 1 In one example of the invention the book pages are arranged inthe conventional manner and these aligned rear edges were coated with afirst adhesive layer made up of 27.8 parts gelatin, 26.0 parts glycerineand 46.2 parts water. Two-thirds of the gelatin had a gel strength of320 as measured by the Bloom gel strength test while one-third had a gelstrength of 185. All parts and percentages herein are by weight.

For the second adhesive layer the adhesive was made up of 44.3 partsgelatin, 34.4 parts glycerine, 21.3 parts water and 10 partscoumarone-indene resin R-l9 (made by The Neville Co.). Thecoumarone-indene resin of this example had a softening point at the balland ring test of about 55 C. (molecular weight about 500 to 600).

The first adhesive was applied to the pages while heated to the properfluidity. Then, the second adhesive was applied over the first adhesive.Finally, a flexible conventional binding was applied over the secondadhesive. The pages of the book were immediately trimmed.

Example 2 In a second example the first adhesive was the same asdescribed in Example 1. The second adhesive was the same as described inExample 1 except here an additional parts of coumarone-indene resin R-29(made by The Neville Co.) was added. This latter resin has a softeningpoint of about 25 C., measured as set out above, and a molecular weightof about 500 to 600.

Example 3 In this example the first adhesive was the same as that ofExample 1 while the second adhesive used the same amounts of ingredientsas set out in Example 1, but half the gelatin had a gel strength of400450 and the other half 185 while two-thirds of the coumarone-indeneresin was R-19 and one-third was R29.

Example 4 In this example the second adhesive contained 54 partsgelatin, 26 parts glycerine, 20 parts water and 15.2 partscoumarone-indene resin. In this example the glycerine and the resin wereas described in the preceding example.

In producing the books of the above examples, the rear edges of thestacked sheets of paper were roughened in the conventional manner inorder to increase the adhesive strength. Also, each adhesive was heatedin its glue pot until the viscosity was about 10,000 centipoises.

Conventional glue or gelatin humectants or plasticizers other thanglycerine may be used, for instance, various glycols, sorbitol and thelike.

Having described my invention as related to the embodiments set outherein, it is my intention that the invention be not limited by any ofthe details of description, unless otherwise specified, but rather beconstrued broadly within its spirit and scope as set out in theaccompanying claims.

I claim:

1. In a book including an assembly of paper sheets having the back edgesaligned and a book cover, an adhesive material combination in the spacebetween said edges and said cover, comprising: a first conventional bookbinding adhesive layer including the usual animalgelatin-glycerine-water combination adhesive; and a second adhesivelayer over said first layer comprising animal gelatin containing about20% moisture, about -90% by weight of said gelatin plus water ofglycerine and about 10-20% by weight of said gelatin plus water plusglycerine of coumarone-indene resin having a ball and ring softeningtemperature of about 25-55 C., said book cover being adhered to saidsecond adhesive layer.

2. The book of claim 1 wherein said cover is water sensitive but isprotected from the water of said first adhesive layer by the presence ofsaid second adhesive layer.

3. The book of claim 1 wherein said resin has a softening temperature ofabout 25 C.

4. The book of claim 1 wherein said resin has a softening temperature ofabout C.

References Cited by the Examiner UNITED STATES PATENTS 1,879,757 9/32Kusch 111 2,277,265 3/42 Zahniser 281-21 2,394,440 2/46 Gordon 260272,463,148 3/49 Caesar 2606 2,512,418 6/50 Cornwell 2606 2,523,860 9/50Budden 28121 2,657,189 10/53 Pinkney 281-21 2,673,845 3/54 Stevens 26027JEROME SCHNALL, Primary Examiner.

LAWRENCE CHARLES, Examiner.

1. IN A BOOK INCLUDING AN ASSEMBLY OF PAPER SHEETS HAVING THE BACK EDGESALIGNED AND A BOOK COVER, AN ADHESIVE MATERIAL COMBINATION IN THE SPACEBETWEEN, SAID EDGES AND SAID COVER, COMPRISING: A FIRST CONVENTIONALBOOK BINDING ADHESIVE LAYER INCLUDING THE USUAL ANIMALGELATIN-GLYCERINE-WATER COMBINATION ADHESIVE; AND A SECOND ADHESIVELAYER OVER SAID FIRST LAYER COMPRISING ANIMAL GELATIN CONTAINING ABOUT20% MOISTURE, ABOUT 50-90% BY WEIGHT OF SAID GELATIN PLUS WATER OFGLYCERINE AND ABOUT 10-20% BY WEIGHT OF SAID GELATIN PLUS WATER PLUSGLYCERINE OF COUMARONE-INDENE RESIN HAVING A BALL AND RING SOFTENINGTEMPERATURE OF ABOUT 25-55*C., SAID BOOK COVER BEING ADHERED TO SAIDSECOND ADHESIVE LAYER.